gdb/progspace.c

   1 /* Program and address space management, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2009-2015 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbcmd.h"
  22 #include "objfiles.h"
  23 #include "arch-utils.h"
  24 #include "gdbcore.h"
  25 #include "solib.h"
  26 #include "gdbthread.h"
  27
  28 /* The last program space number assigned.  */
  29 int last_program_space_num = 0;
  30
  31 /* The head of the program spaces list.  */
  32 struct program_space *program_spaces;
  33
  34 /* Pointer to the current program space.  */
  35 struct program_space *current_program_space;
  36
  37 /* The last address space number assigned.  */
  38 static int highest_address_space_num;
  39
  40 \f
  41
  42 /* Keep a registry of per-program_space data-pointers required by other GDB
  43    modules.  */
  44
  45 DEFINE_REGISTRY (program_space, REGISTRY_ACCESS_FIELD)
  46
  47 /* An address space.  It is used for comparing if pspaces/inferior/threads
  48    see the same address space and for associating caches to each address
  49    space.  */
  50
  51 struct address_space
  52 {
  53   int num;
  54
  55   /* Per aspace data-pointers required by other GDB modules.  */
  56   REGISTRY_FIELDS;
  57 };
  58
  59 /* Keep a registry of per-address_space data-pointers required by other GDB
  60    modules.  */
  61
  62 DEFINE_REGISTRY (address_space, REGISTRY_ACCESS_FIELD)
  63
  64 \f
  65
  66 /* Create a new address space object, and add it to the list.  */
  67
  68 struct address_space *
  69 new_address_space (void)
  70 {
  71   struct address_space *aspace;
  72
  73   aspace = XCNEW (struct address_space);
  74   aspace->num = ++highest_address_space_num;
  75   address_space_alloc_data (aspace);
  76
  77   return aspace;
  78 }
  79
  80 /* Maybe create a new address space object, and add it to the list, or
  81    return a pointer to an existing address space, in case inferiors
  82    share an address space on this target system.  */
  83
  84 struct address_space *
  85 maybe_new_address_space (void)
  86 {
  87   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
  88
  89   if (shared_aspace)
  90     {
  91       /* Just return the first in the list.  */
  92       return program_spaces->aspace;
  93     }
  94
  95   return new_address_space ();
  96 }
  97
  98 static void
  99 free_address_space (struct address_space *aspace)
 100 {
 101   address_space_free_data (aspace);
 102   xfree (aspace);
 103 }
 104
 105 int
 106 address_space_num (struct address_space *aspace)
 107 {
 108   return aspace->num;
 109 }
 110
 111 /* Start counting over from scratch.  */
 112
 113 static void
 114 init_address_spaces (void)
 115 {
 116   highest_address_space_num = 0;
 117 }
 118
 119 \f
 120
 121 /* Adds a new empty program space to the program space list, and binds
 122    it to ASPACE.  Returns the pointer to the new object.  */
 123
 124 struct program_space *
 125 add_program_space (struct address_space *aspace)
 126 {
 127   struct program_space *pspace;
 128
 129   pspace = XCNEW (struct program_space);
 130
 131   pspace->num = ++last_program_space_num;
 132   pspace->aspace = aspace;
 133
 134   program_space_alloc_data (pspace);
 135
 136   pspace->next = program_spaces;
 137   program_spaces = pspace;
 138
 139   return pspace;
 140 }
 141
 142 /* Releases program space PSPACE, and all its contents (shared
 143    libraries, objfiles, and any other references to the PSPACE in
 144    other modules).  It is an internal error to call this when PSPACE
 145    is the current program space, since there should always be a
 146    program space.  */
 147
 148 static void
 149 release_program_space (struct program_space *pspace)
 150 {
 151   struct cleanup *old_chain = save_current_program_space ();
 152
 153   gdb_assert (pspace != current_program_space);
 154
 155   set_current_program_space (pspace);
 156
 157   breakpoint_program_space_exit (pspace);
 158   no_shared_libraries (NULL, 0);
 159   exec_close ();
 160   free_all_objfiles ();
 161   if (!gdbarch_has_shared_address_space (target_gdbarch ()))
 162     free_address_space (pspace->aspace);
 163   clear_section_table (&pspace->target_sections);
 164   clear_program_space_solib_cache (pspace);
 165     /* Discard any data modules have associated with the PSPACE.  */
 166   program_space_free_data (pspace);
 167   xfree (pspace);
 168
 169   do_cleanups (old_chain);
 170 }
 171
 172 /* Copies program space SRC to DEST.  Copies the main executable file,
 173    and the main symbol file.  Returns DEST.  */
 174
 175 struct program_space *
 176 clone_program_space (struct program_space *dest, struct program_space *src)
 177 {
 178   struct cleanup *old_chain;
 179
 180   old_chain = save_current_program_space ();
 181
 182   set_current_program_space (dest);
 183
 184   if (src->pspace_exec_filename != NULL)
 185     exec_file_attach (src->pspace_exec_filename, 0);
 186
 187   if (src->symfile_object_file != NULL)
 188     symbol_file_add_main (objfile_name (src->symfile_object_file), 0);
 189
 190   do_cleanups (old_chain);
 191   return dest;
 192 }
 193
 194 /* Sets PSPACE as the current program space.  It is the caller's
 195    responsibility to make sure that the currently selected
 196    inferior/thread matches the selected program space.  */
 197
 198 void
 199 set_current_program_space (struct program_space *pspace)
 200 {
 201   if (current_program_space == pspace)
 202     return;
 203
 204   gdb_assert (pspace != NULL);
 205
 206   current_program_space = pspace;
 207
 208   /* Different symbols change our view of the frame chain.  */
 209   reinit_frame_cache ();
 210 }
 211
 212 /* A cleanups callback, helper for save_current_program_space
 213    below.  */
 214
 215 static void
 216 restore_program_space (void *arg)
 217 {
 218   struct program_space *saved_pspace = arg;
 219
 220   set_current_program_space (saved_pspace);
 221 }
 222
 223 /* Save the current program space so that it may be restored by a later
 224    call to do_cleanups.  Returns the struct cleanup pointer needed for
 225    later doing the cleanup.  */
 226
 227 struct cleanup *
 228 save_current_program_space (void)
 229 {
 230   struct cleanup *old_chain = make_cleanup (restore_program_space,
 231                                             current_program_space);
 232
 233   return old_chain;
 234 }
 235
 236 /* Returns true iff there's no inferior bound to PSPACE.  */
 237
 238 static int
 239 pspace_empty_p (struct program_space *pspace)
 240 {
 241   if (find_inferior_for_program_space (pspace) != NULL)
 242       return 0;
 243
 244   return 1;
 245 }
 246
 247 /* Prune away automatically added program spaces that aren't required
 248    anymore.  */
 249
 250 void
 251 prune_program_spaces (void)
 252 {
 253   struct program_space *ss, **ss_link;
 254   struct program_space *current = current_program_space;
 255
 256   ss = program_spaces;
 257   ss_link = &program_spaces;
 258   while (ss)
 259     {
 260       if (ss == current || !pspace_empty_p (ss))
 261         {
 262           ss_link = &ss->next;
 263           ss = *ss_link;
 264           continue;
 265         }
 266
 267       *ss_link = ss->next;
 268       release_program_space (ss);
 269       ss = *ss_link;
 270     }
 271 }
 272
 273 /* Prints the list of program spaces and their details on UIOUT.  If
 274    REQUESTED is not -1, it's the ID of the pspace that should be
 275    printed.  Otherwise, all spaces are printed.  */
 276
 277 static void
 278 print_program_space (struct ui_out *uiout, int requested)
 279 {
 280   struct program_space *pspace;
 281   int count = 0;
 282   struct cleanup *old_chain;
 283
 284   /* Compute number of pspaces we will print.  */
 285   ALL_PSPACES (pspace)
 286     {
 287       if (requested != -1 && pspace->num != requested)
 288         continue;
 289
 290       ++count;
 291     }
 292
 293   /* There should always be at least one.  */
 294   gdb_assert (count > 0);
 295
 296   old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, count, "pspaces");
 297   ui_out_table_header (uiout, 1, ui_left, "current", "");
 298   ui_out_table_header (uiout, 4, ui_left, "id", "Id");
 299   ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 300   ui_out_table_body (uiout);
 301
 302   ALL_PSPACES (pspace)
 303     {
 304       struct cleanup *chain2;
 305       struct inferior *inf;
 306       int printed_header;
 307
 308       if (requested != -1 && requested != pspace->num)
 309         continue;
 310
 311       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 312
 313       if (pspace == current_program_space)
 314         ui_out_field_string (uiout, "current", "*");
 315       else
 316         ui_out_field_skip (uiout, "current");
 317
 318       ui_out_field_int (uiout, "id", pspace->num);
 319
 320       if (pspace->pspace_exec_filename)
 321         ui_out_field_string (uiout, "exec", pspace->pspace_exec_filename);
 322       else
 323         ui_out_field_skip (uiout, "exec");
 324
 325       /* Print extra info that doesn't really fit in tabular form.
 326          Currently, we print the list of inferiors bound to a pspace.
 327          There can be more than one inferior bound to the same pspace,
 328          e.g., both parent/child inferiors in a vfork, or, on targets
 329          that share pspaces between inferiors.  */
 330       printed_header = 0;
 331       for (inf = inferior_list; inf; inf = inf->next)
 332         if (inf->pspace == pspace)
 333           {
 334             if (!printed_header)
 335               {
 336                 printed_header = 1;
 337                 printf_filtered ("\n\tBound inferiors: ID %d (%s)",
 338                                  inf->num,
 339                                  target_pid_to_str (pid_to_ptid (inf->pid)));
 340               }
 341             else
 342               printf_filtered (", ID %d (%s)",
 343                                inf->num,
 344                                target_pid_to_str (pid_to_ptid (inf->pid)));
 345           }
 346
 347       ui_out_text (uiout, "\n");
 348       do_cleanups (chain2);
 349     }
 350
 351   do_cleanups (old_chain);
 352 }
 353
 354 /* Boolean test for an already-known program space id.  */
 355
 356 static int
 357 valid_program_space_id (int num)
 358 {
 359   struct program_space *pspace;
 360
 361   ALL_PSPACES (pspace)
 362     if (pspace->num == num)
 363       return 1;
 364
 365   return 0;
 366 }
 367
 368 /* If ARGS is NULL or empty, print information about all program
 369    spaces.  Otherwise, ARGS is a text representation of a LONG
 370    indicating which the program space to print information about.  */
 371
 372 static void
 373 maintenance_info_program_spaces_command (char *args, int from_tty)
 374 {
 375   int requested = -1;
 376
 377   if (args && *args)
 378     {
 379       requested = parse_and_eval_long (args);
 380       if (!valid_program_space_id (requested))
 381         error (_("program space ID %d not known."), requested);
 382     }
 383
 384   print_program_space (current_uiout, requested);
 385 }
 386
 387 /* Simply returns the count of program spaces.  */
 388
 389 int
 390 number_of_program_spaces (void)
 391 {
 392   struct program_space *pspace;
 393   int count = 0;
 394
 395   ALL_PSPACES (pspace)
 396     count++;
 397
 398   return count;
 399 }
 400
 401 /* Update all program spaces matching to address spaces.  The user may
 402    have created several program spaces, and loaded executables into
 403    them before connecting to the target interface that will create the
 404    inferiors.  All that happens before GDB has a chance to know if the
 405    inferiors will share an address space or not.  Call this after
 406    having connected to the target interface and having fetched the
 407    target description, to fixup the program/address spaces mappings.
 408
 409    It is assumed that there are no bound inferiors yet, otherwise,
 410    they'd be left with stale referenced to released aspaces.  */
 411
 412 void
 413 update_address_spaces (void)
 414 {
 415   int shared_aspace = gdbarch_has_shared_address_space (target_gdbarch ());
 416   struct program_space *pspace;
 417   struct inferior *inf;
 418
 419   init_address_spaces ();
 420
 421   if (shared_aspace)
 422     {
 423       struct address_space *aspace = new_address_space ();
 424
 425       free_address_space (current_program_space->aspace);
 426       ALL_PSPACES (pspace)
 427         pspace->aspace = aspace;
 428     }
 429   else
 430     ALL_PSPACES (pspace)
 431       {
 432         free_address_space (pspace->aspace);
 433         pspace->aspace = new_address_space ();
 434       }
 435
 436   for (inf = inferior_list; inf; inf = inf->next)
 437     if (gdbarch_has_global_solist (target_gdbarch ()))
 438       inf->aspace = maybe_new_address_space ();
 439     else
 440       inf->aspace = inf->pspace->aspace;
 441 }
 442
 443 /* Save the current program space so that it may be restored by a later
 444    call to do_cleanups.  Returns the struct cleanup pointer needed for
 445    later doing the cleanup.  */
 446
 447 struct cleanup *
 448 save_current_space_and_thread (void)
 449 {
 450   struct cleanup *old_chain;
 451
 452   /* If restoring to null thread, we need to restore the pspace as
 453      well, hence, we need to save the current program space first.  */
 454   old_chain = save_current_program_space ();
 455   /* There's no need to save the current inferior here.
 456      That is handled by make_cleanup_restore_current_thread.  */
 457   make_cleanup_restore_current_thread ();
 458
 459   return old_chain;
 460 }
 461
 462 /* See progspace.h  */
 463
 464 void
 465 switch_to_program_space_and_thread (struct program_space *pspace)
 466 {
 467   struct inferior *inf;
 468
 469   inf = find_inferior_for_program_space (pspace);
 470   if (inf != NULL && inf->pid != 0)
 471     {
 472       struct thread_info *tp;
 473
 474       tp = any_live_thread_of_process (inf->pid);
 475       if (tp != NULL)
 476         {
 477           switch_to_thread (tp->ptid);
 478           /* Switching thread switches pspace implicitly.  We're
 479              done.  */
 480           return;
 481         }
 482     }
 483
 484   switch_to_thread (null_ptid);
 485   set_current_program_space (pspace);
 486 }
 487
 488 \f
 489
 490 /* See progspace.h.  */
 491
 492 void
 493 clear_program_space_solib_cache (struct program_space *pspace)
 494 {
 495   VEC_free (so_list_ptr, pspace->added_solibs);
 496
 497   free_char_ptr_vec (pspace->deleted_solibs);
 498   pspace->deleted_solibs = NULL;
 499 }
 500
 501 \f
 502
 503 void
 504 initialize_progspace (void)
 505 {
 506   add_cmd ("program-spaces", class_maintenance,
 507            maintenance_info_program_spaces_command,
 508            _("Info about currently known program spaces."),
 509            &maintenanceinfolist);
 510
 511   /* There's always one program space.  Note that this function isn't
 512      an automatic _initialize_foo function, since other
 513      _initialize_foo routines may need to install their per-pspace
 514      data keys.  We can only allocate a progspace when all those
 515      modules have done that.  Do this before
 516      initialize_current_architecture, because that accesses exec_bfd,
 517      which in turn dereferences current_program_space.  */
 518   current_program_space = add_program_space (new_address_space ());
 519 }